1900, Russell attended the international philosophy conference held in Paris, where he met the great mathematician and logician Peano. During the meeting, he was able to talk with famous mathematicians like piano and Gottlob Frege, which prompted Russell to write one of his major works, namely "Principles of Mathematics" which he and alfred whitehead co-authored in1910/913. This book is an in-depth discussion of Frege's argument that "all arithmetic is an extension of the basic principles of logic". Russell proved the power of symbolic logic as a tool of philosophical analysis, which may be his contribution to the history of philosophy.
One of the main aspects of Russell's general view is to believe that philosophy is subordinate to science. Russell believes that philosophy should be based on science, not anything else, because compared with philosophy, science has less risk of making mistakes. Many analytical philosophers, including him, believe that "science is innocent unless proven guilty; Philosophy is guilty unless proven innocent. " Russell regarded philosophy as a subsidiary of science, and during the period when Russell wrote this book, science developed very rapidly, which partly explained why Russell's philosophy changed so quickly. A very unfriendly critic said that Russell started his philosophical career by writing a book every year to refute his views in the last year's book. Indeed, it is precisely because of repeated changes that it is difficult for people to say exactly what Russell's philosophy is. But despite these changes, there are still some similarities in his views. He has always believed that philosophy is essentially analytical, which he has always insisted on. 1924 He wrote:
Although building a grand system is what philosophy should do, I don't think it is the most important thing. In my opinion, the most important thing is to criticize and sort out those views that are increasingly considered to be basic and undoubtedly accepted. I can give the following examples: thought, matter, consciousness, knowledge, experience, cause and effect, will and time. I think all these ideas are inaccurate, rough and vague in nature and can't be part of any precise science.
Russell's philosophy has always adhered to Occam's razor principle. As we said before, this principle requires theoretical simplicity and suggests "Don't add entities unless necessary". Therefore, Russell concluded: "whenever possible, we should replace the inference of unknown entities with the structure of known entities." He believes that we should all explain the world with the characteristics that people are already familiar with, and we should avoid the temptation to assume the existence of things that we cannot know, unless undeniable facts or convincing logical arguments force us to do so.
Russell's "description theory" represents his viewpoint and is regarded as his great contribution to philosophy. We can express his view in this way: philosophers have been entangled in the logical meaning of the concept of existence since Plato, and many people, including Plato, have to create a huge metaphysical system to solve the problems brought about by the concept of existence. Russell found that most of these systems are too metaphysical (that is, they seriously violate Occam's razor principle) or too contradictory. Let's deal with three such problems.
1. I said "Jinshan does not exist". You ask, "What doesn't exist?" I replied, "Jinshan." But in this way, I seem to give what I just denied a kind of existence (what is that thing? )。 In addition, if I say "unicorn doesn't exist" and "square doesn't exist", I seem to be saying that Jinshan, unicorn and square are three different things, but in fact, they don't exist! Platonists' solution to this problem is that words such as "Jinshan" refer to imaginary things that exist in the pure world of existence, not the real world. Obviously, this view is too metaphysical for Luo Su and needs to be cleaned up with Occam razor.
2. Consider this sentence: "Scott is the author of waverley." Logicians believe that if these two words refer to the same object, then the two words can be exchanged without changing the meaning or truth value of the proposition expressed in the sentence. (if A=B, then [a = b] = [b = a] = [a = a] = [b = b]. For example, the novel waverley was published anonymously, and many people want to know who wrote it. King George IV wanted to know especially, because he wanted to find out who was slandering his ancestors. The king didn't want to know whether the author of Waverly was the author of Waverly or whether Mr. White Scott was Mr. White Scott. (Although in fact Plato or Leibniz will answer this question: All sentences are propositions "Everything is everything" or "A=A". But such a metaphysical "solution" will never satisfy people like Bertrand Russell. )
3. Think about this sentence: "The king of France today is bald." This assertion seems wrong (because there is no such person), but according to law of excluded middle, the negation of any false proposition must be true, so the assertion that "the French king is not bald today" must be true. However, to be sure, this sentence is also false. Do we have to accept metaphysics to solve this problem again? That is to say, are we going to put the object referred to in the sentence "King of France today", together with such conceptual features as baldness or hair, into the conceptual world of existence? That's what Platonic logicians think. Russell doesn't think so. (Russell thinks that hegelianism scholars will find the answer to this question through a joint question: "The French king is wearing a wig today." )
Therefore, we have three different logical problems about the concept of existence. Russell's description theory aims to reveal the real logical structure contained in various propositions about existence, so as to dispel specious contradictions and metaphysical puzzles. Russell found a formula that he thought could complete the work:
There is an entity C, so the sentence "X is Y" is true if and only if X = C. ..
In this formula, C is an entity, Y is a feature written in the form of adjectives, and X is the subject modified by adjectives. For example, the sentence "Jinshan does not exist" was translated by Russell as: "There is no entity C, which makes the sentence" X is Jinshan "valid if and only if X = C". In other words, the word "Jinshan" that violates the principle (because it seems to refer to an entity, that is, to name a thing) is transformed into a description (Jinshan and Mountain). What this proposition really wants to say is that Note that the concept of existence is analyzed from the word "Jinshan".
Regarding the second question, the sentence "Scott is the author of waverley" is changed to "there is an entity C, which makes' X wrote waverley' valid if and only if X is C; And C is Scott. " Therefore, the feature of "author's" is to describe an existing entity (Scott) in detail, rather than to describe it in the form of pure repetition in the same language. Note again that the concept of existence has been analyzed from The Author of waverley.
Finally, the sentence "the king of France is bald today" means "there is an entity C, so that' X is king, French and bald' is true if and only if X=C". But no entity can correctly apply this description to it, so this sentence is false; The denial of this sentence is also false, because there is no entity that can be described as "king, French, bald". So we can draw the conclusion that these two sentences are false, and they don't violate law of excluded middle.
In these three examples, Russell used Occam's razor and removed the concept of existence. Russell even made the following comments on his answer without modesty: "This answer clarifies the ideological confusion about' existence' for two thousand years since Plato's Tyades."
Many of Russell's philosophical thoughts are very specialized, but as a professional philosopher, he is in sharp contrast with Russell as a social critic and activist. He spent some time in prison as an anti-war activist during the First World War. He was disappointed that Moore entered the war as a British officer; He was even more disappointed that his student Wittgenstein returned to Europe to join the Austrian army and became a soldier. ) Russell is a severe critic of American and Soviet social policies. After World War II, he became an active anti-nuclear weapon. (At the age of 89, Russell protested that the United States placed nuclear weapons in Britain and incited public citizens to disobey orders. He was arrested and imprisoned after an illegal rally in Hyde Park; In his nineties, he actively publicized and opposed the involvement of the United States in the Vietnam War. )
In this respect, Russell is just the opposite of Moore. We can see that Moore has never found anything that can attract his wisdom and enthusiasm except what philosophers talk about. When journalist Ved Mehta went to Rossu's house to interview his philosophy at 1960, Russell met him at the door and asked him if he had heard of the atomic bomb. Russell told Meta that faced with the danger of being involved in the nuclear crisis, there was no time to discuss philosophy.